Should you be washing your hands or bathing your children with antibacterial soap?

The University of Texas student government and Canadian leaders say no. Many environmentalists and scientists agree.

The concern is triclosan, an antibacterial chemical used for more than 30 years in soaps, toothpastes, lotions and deodorant and marketed as a germ killer. But antibacterial soap does not work any better than regular soap, according to the Centers for Disease Control and Prevention and other studies.

And there are growing concerns about the effect triclosan has on humans and what the chemical runoff does to plants and animals in lakes, streams and rivers.

During the past couple of years, Colgate-Palmolive, GlaxoSmithKline and Johnson & Johnson have removed triclosan from some of their products.

UT made news recently when student leaders passed a resolution calling for administrators to ban antibacterial soap from campus. It may have been more of a symbolic move because in 2008 the university began phasing out the use of antibacterial soap, mostly because of costs.

Earlier this month the Canadian government urged companies to voluntarily remove triclosan from household products because of concern about its toxicity to aquatic organisms. The Canadian action followed a government assessment that the current level of triclosan is not harmful to human health, but in significant amounts it can harm the environment.

The CDC says more research is needed to assess the human health effects of exposure to triclosan, which is also classified as a pesticide. Studies are under way at the Environmental Protection Agency and the Food and Drug Administration.

Researchers are looking at how the antimicrobial affects hormonal and immune systems and the chemical's relationship to asthma and allergies. And could killing a specific bacterium, which triclosan does, tip a body's balance to cause long-term health problems?

Having a superfluous chemical in our soaps is a potential risk we don't need, said Aiello, associate professor of epidemiology.

"And I say 'potential risk' because some of the work has been done in a lab setting, but it hasn't been well studied in humans," she said. "However, a lot of things that we have identified as harmful have first been identified in a lab setting and then demonstrated among humans."

While Starke sees no need for antibacterial products for home use, he said, "this isn't something that I lose sleep over."

"With all the problems that we have in infection control and infectious diseases, this is not at the top of the list. But antibacterial soap is just not necessary," he said. "It's expensive, and it's exposing people to chemicals for no benefit. It's not what we are supposed to do."